When you eat, you use up every drop of water your food required to grow. And depending on your choices—roasted broccoli versus a juicy steak—a meal might consume a few liters of water, or a few hundred. Some plants sip gingerly from the soil, while others gulp; and animals not only drink water, but ingest it indirectly through the feed they eat. In a thirsty world, we should choose our foods wisely. To help, Popular Science calculated how many liters of water go into 100 calories’ worth of the following staples.
Broccoli seems like a wonder food, based on the calories you get out for the water you put in. And even though 100 calories of the veggie weighs in at more than half a head, this crunchy snack doesn’t need a ton of flow to grow.
Chickens not only drink water, but they also munch water-requiring feed. But they don’t do so for long: The average broiler takes a mere five weeks to reach its market weight of 5 pounds. After that, the eater becomes the eaten.
Apple trees are picky growers: They don’t thrive in too-wet soil, but they do require irrigation in too-dry soil. Yet, on the liters-per-100-calories scale, they use nearly as much water as chicken. That’s because the fruit provides less energy.
Wheat usually grows in spring and fall, so farmers needn’t water it during the blistering days of summer. Wheat also has a deep and efficient root system, and in ideal circumstances, doesn’t even require additional irrigation.
Crickets are efficient little bugs. Sixty percent protein by weight, they require fewer than four liters of water per pound of protein. Even better, they reach adulthood in just six weeks. The challenge is convincing people to eat them.
Cattle are natural water guzzlers, drinking nearly 130 liters per day. What’s worse, a 1,200-pound cow can eat more than 20 pounds of hay while the sun shines, which incurs an H2O penalty of thousands of additional liters.
This article was originally published in the March/April 2017 issue of Popular Science, under the title “But How Much Does Food Drink?”